Defiant relatives of Sept. 11 victims vowed yesterday to fight to set aside the entire World Trade Center site for a memorial to the terror dead.

“That site, the 16 acres [where the trade center stood], no longer belongs to the state of New York, no longer belongs to the city,” said Steve Campbell, a Brooklyn cop whose wife Jill, 31, died in the attack.

“It belongs to me and to my 14-month-old son, my mother-in-law and father-in-law and the families of the other victims.”

Campbell condemned proposals to erect new buildings on part of the site.

About 50 family members met last night in a SoHo office to discuss ideas for a memorial.

Monica Iken, who founded a relatives group called September’s Mission, said she will meet with Gov. Pataki to pass along some of the ideas, as well as the determination of many relatives to maintain the WTC site as “sacred ground.”